The present invention relates generally to a method and device for feeding liquid fuel to engines, particularly to a method and device for feeding fuel to a diesel engine and specifically for feeding fuel to a large diesel engine.
Large diesel engines have many uses including stationary applications, marine applications, and earth-moving equipment applications. The major investment made by the user of a diesel engine requires that the engine be operational when needed. This is necessary so that the engine may deliver the intended benefits and thereby provide a return on the investment of the user. This operational readiness is further improved when service time or downtime is kept to a minimum. Road construction activities make great use of construction equipment powered with large diesel engines. Thus, the public interest in timely completion of road construction projects is served by minimizing the downtime of the earth-moving equipment.
The fuel system of a large diesel engine includes multiple stages of fuel filtering in order to provide sufficiently clean fuel to the engine fuel injectors. The extensive fuel filtering needs make it necessary to service the fuel filters frequently. Fuel filter servicing generally includes replacement of the microscreen filtering element. Other events, for example, an engine running out of fuel, also require fuel system servicing. The size of the equipment, its limited mobility and the need to minimize equipment downtime make field servicing as opposed to shop servicing a necessary approach. Servicing tools, techniques and procedures must therefore be designed for variable field use conditions such as wide temperature ranges, dusty environments and the like.
In the past after servicing of the fuel system, the fuel pump must be operated for an extended time. This is necessary because the pump must draw liquid fuel from the fuel tank through the multiple microscreen fuel filter stages and deliver the fuel to the engine. The resistance to flow of the small fuel passages in the microscreen filters causes the extended pumping time. The pumping time is further extended when low ambient temperatures increase the viscosity of the fuel.
The extended pumping time results in excessive downtime. In addition, the extended pumping time causes an excessive drain on the battery that powers the fuel pump and excessive wear on the fuel pump components which results in a shortened service life for the battery and the fuel pump.
Thus a need exists in the field of servicing fuel systems on large diesel engines for a fuel feeding device and method that greatly reduces the engine downtime. Further a need exists for a fuel feeding device and method that is simple to use under varying field servicing conditions, is low cost, and is inherently safe for use by the diesel engine service person.